This section provides background information related to the present disclosure which is not necessarily prior art.
Combustion engines are known to produce emissions that may be harmful to the environment. In an effort to decrease the environmental impact that an engine may have, exhaust after-treatment systems have undergone comprehensive evaluation and development. Various components that assist in treating engine emission include oxidation and reduction catalysts. Dependent on the size of the engine application, the cost of these components can increase greatly. In this regard, larger engine applications such as locomotive, marine, and large horsepower stationary applications can produce substantially more exhaust emissions than, for example, a tractor trailer engine application. The exhaust after-treatment systems, therefore, are generally larger in scale to satisfactorily reduce the harmful emissions produced by these large-scale applications. As the scale of the after-treatment system increases, however, the cost to produce, install, and service such a system increases greatly. It is desirable, therefore, to produce an exhaust after-treatment system that is more conventional in scale, while still being able to reduce the effects of harmful emissions emitted by large engine applications.